Metastable Metallic Phase of a Bilayer Blue Phosphorene Induced by Interlayer Bonding and Intralayer Charge Redistributions

Abstract

We have carried out diffusion Monte Carlo calculations for an A1B–1-stacked bilayer blue phosphorene to find that it undergoes a semiconductor–metal transition as the interlayer distance decreases. While the most stable bilayer structure is a semiconducting one with two monolayers coupled through a weak van der Waals interaction, the metallic bilayer at a shorter interlayer distance is found to be only metastable. This is in contrast to a recent theoretical prediction based on a random phase approximation that the metallic phase would be the most stable bilayer configuration of blue phosphorene. Our analysis of charge density distributions reveals that the metastable metallic phase is induced by interlayer chemical bonding and intralayer charge redistributions. This study enriches our understanding of interlayer binding of a blue phosphorene and contributes to the establishment of correct energetic order between its different phases, which will be essential in devising an experimental pathway for a metallic phosphorene.

The structural and electronic richness of buckled honeycomb AsP bilayers

“…This is important to note, as two high-precision methods for layered structures yield different results, as shown in a recent publication on blue phosphorene bilayers. 46 Given the discrepancy between different levels of theory and to confirm the reliability of our results, we performed additional computations at the ACFDT-RPA level based on PBE0 orbitals for three different systems: the lowest energy forms of group I and II (A −1 A′ −1 and A′ −1 B 1 ), and A′ 1 B′ −1 of group III. As shown in Table S1, † the trend of the relative energies between the three systems matches perfectly with those obtained with RPA and PBE orbitals, confirming that the lowest-lying energy form belongs to group I instead of A′ 1 B′ −1 of group III, as indicated by SCAN + rVV10.…”

Semiconductor-to-metal transition from monolayer to bilayer blue phosphorous induced by extremely strong interlayer coupling: a first-principles study

“…Our tests show that the relative stabilities of the metallic and semiconducting phases depend on the used func-tionals (see the ESI †) in agreement with the work in ref. 28. However, when taking temperature effects into account, we find that the semiconducting phase will automatically transform into the metallic phase no matter what functionals are used, as demonstrated by our molecular dynamical simulations at 300 K (see the ESI †), indicating that the metallic phase is likely to be obtained if bilayer blue-P can be made.…”

“…However, after studying diverse stacking modes of bilayer blue-P, J. Arcudia et al reported that the most stable stacking configuration shows metallic behavior with the A 1 B −1 arrangement. 27 Another work by J. Ahn et al reported that the most stable bilayer blue-P is semiconducting with a much larger layer distance 28 by considering the many-body effects. Our tests show that the relative stabilities of the metallic and semiconducting phases depend on the used func-tionals (see the ESI †) in agreement with the work in ref.…”

Electrostatic Gating of Phosphorene Polymorphs

“…Among layered materials, phosphorene is a promising candidate due to rich geometric structures that is leading to various polymorphs and polytypes − while having none of the obstacles exhibited by other two-dimensional materials. − Several structurally different two-dimensional polymorphs of phosphorus namely, α-P, β-P, γ-P, δ-P, ε-P, τ-P, η-P, θ-P, σ-P, ϕ-P, tricycle-type red phosphorene (R-P), square-octagon phosphorene (O–P) and hexagonal-star phosphorene (H–P) have been investigated using first principle methods. − Most of these two-dimensional polymorphic materials are semiconductors with a band gap in the range of 0.4 to 2.1 eV. ,− We recall that α-P and β-P have been prepared experimentally, while other allotropes have not yet been synthesized . According to the polytypism definition, the individual phosphorene allotropes can be coupled through noncovalent interactions leading to bi/tri/few layer phases up to the bulk material .…”